ABSTRACT
Objective To observe the current status of secondary prevention medication usage and their relation with on-treatment platelet reactivity in patients with Acute Coronary Syndrome(ACS) treated with aspirin and clopidogrel. Methods A total of 176 patients hospitalized from 2014 to 2015 due to ACS in the Department of Cardiology, Peking University People's Hospital were enrolled and on-treatment platelet reactivity was tested by thromboelastography(TEG)and CYP2C19*2,*3 and*17 alleles were analysed. Details of secondary prevention medication and patients' clinical characteristics were recorded. The relation of secondary prevention medication and on-treatment platelet reactivity was analyzed by multi-logistic regression after adjusting for CYP2C19 alleles and clinical characteristics covariates.Results A 94.89% of patients was treated with statins while 80.68% with beta blocker. The platelet inhibition rate were (45.33±28.78)% and the high on-treatment platelet reactivity (HTPR) rate tested by TEG was 37.50%. In the multivariate logistic regression analysis, usage of β-blockers during hospitalization as well as phenotypes of CYP2C19*2,*3 and *17,clinical presentation with ST-segment elevation myocardial infarction and the length of stents were associated with HTPR defi ned by TEG. The percentage of HTPR rate was signifi cantly lower in patients treated with than those without β-blockers (72.73% vs. 85.45%,OR 0.18,95%CI 0.06-0.53,P=0.002)after adjusting genetic factors and other covariates.Conclusions There was a signifi cant correlation between beta blockers usage and high clopidogrel on-treatment platelet reactivity.
ABSTRACT
<p><b>BACKGROUND</b>To investigate the contributions of CYP2C19 polymorphisms to the various clopidogrel responses tested by thrombelastography (TEG) in Chinese patients with the acute coronary syndrome (ACS).</p><p><b>METHODS</b>Patients were screened prospectively with ACS diagnose and were treated with clopidogrel and aspirin dual antiplatelet therapy. CYP2C19 loss of function (LOF) and gain of function (GOF) genotype, adenosine 5'-diphosphate (ADP)-channel platelet inhibition rate (PIR) tested by TEG and the occurrence of 3-month major adverse cardiovascular events and ischemic events were assessed in 116 patients.</p><p><b>RESULTS</b>High on-treatment platelet reactivity (HTPR) prevalence defined by PIR <30% by TEG in ADP-channel was 32.76% (38/116). With respect to the normal wild type, CYP2C19*2, and *3 LOF alleles, and *17 GOF alleles, patients were classified into three metabolism phenotypes: 41.38% were extensive metabolizers (EMs), 56.90% were intermediate metabolizers (IMs), and 1.72% were poor metabolizers (PMs). Of the enrolled patients, 31.47%, 5.17%, and 0.43%, respectively, were carriers of *2, *3, and *17 alleles. The HTPR incidence differed significantly according to CYP2C19 genotypes, accounting for 18.75%, 41.54%, and 100.00% in EMs, IMs, and PMs, respectively. Eighteen (17.24%) ischemic events occurred during the 3-month follow-up, and there was a significant difference in ischemic events between HTPR group and nonhigh on-treatment platelet reactivity group.</p><p><b>CONCLUSIONS</b>Genetic CYP2C19 polymorphisms are relative to the inferior, the antiplatelet activity after clopidogrel admission and may increase the incidence of ischemic events in patients with ACS.</p>